"Oxalate stones" refers to small, hard deposits that can form in certain parts of the body, like the kidneys. They are made up of a substance called oxalate that can accumulate and cause discomfort or blockages.
Full definition
The amount of calcium in the urine is a major factor in
calcium oxalate stone formation in pets and humans.
Potassium citrate helps decrease the possibility of calcium
oxalate stone formation and cranberry extract has been shown to enhance urinary tract health.
Quest Diagnostics offers the tests to people who have a calcium
oxalate stone problem but their veterinary division does not.
A Canadian studies did not find an increase in the frequency of calcium
oxalate stones in the general cat population between 1998 and 2008.
When calcium
oxalate stones form in a cat's kidneys, they can eventually damage those organs beyond repair.
There are a few cats that
develop oxalate stones because their blood calcium levels are abnormally high (hypercalcemia).
Most cats that initially come to veterinarians
with oxalate stone problems have urine pH of 6.5 or less.
It may turn out that some of my suggestion are unnecessary and that some are ineffective; but until veterinarians better understand why some cats form calcium
oxalate stones on one diets and lifestyle, while others with that same diet and lifestyle do not, this is the best advice I can give you.
This is especially true
when oxalate stones remain in your cat's kidneys or when there was any prior elevation of blood BUN or creatinine levels.
Fewer urinations and lower urine quantities were found to be associated with greater potential
for oxalate stone formation (RSS index).
Excessive calcium supplementation is associated with the development of canine hip dysplasia and may increase the risk of calcium
oxalate stone development in the urinary tract.
Increasing the magnesium content in the food and by making cats drink more water before and after meals can assist with
dissolving oxalate stones.
There are a few dogs that develop
oxalate stones because their blood calcium levels are abnormally high (hypercalcemia).
Also, they tend to form in the kidneys in humans and bladder in canines, so it may be risky to draw too many conclusions about calcium
oxalate stone disease processes from human studies.
Since diet helps to keep struvite stones from forming (although it is still possible), most dogs have the harder to
treat oxalate stones.
No veterinarian has a foolproof plan to guarantee that your dog will not produce
oxalate stones again.
This is especially true when
oxalate stones remain in your dog's kidneys or when there was any prior elevation of blood BUN or creatinine levels.
However, you should use caution in feeding sweet potatoes to dogs who are prone to forming calcium
oxalate stones since they are high in oxalate.
These diets are a Godsend for dealing with struvite stones; they are not nearly as effective in
managing oxalate stones.
If you do not make major changes in your pet's lifestyle and nutrition, the likelihood of your pet
reforming oxalate stones is quite high.
Control urine pH: acidic urine helps prevent urinary tract infections, dissolves both phosphate and struvite stones, and will not
cause oxalate stones.
By changing the prescription diets yet again, the number of calcium
oxalate stones decreased, and we are once again seeing a higher percentage of struvite stones.
- to
reduce oxalate stone formation, through its low level of calcium and vitamin D, and its urine alkalising properties.
In a study presented by Jody Lulich's group at the University of Minnesota at the 2004 meeting of the American College of Veterinary Internal Medicine, 24 out of 33 Bichons had
oxalate stone recurrence after cystotomy (37 % had had their first recurrence in the first year after surgery, by the end of the second year 57 % had recurred, and by the end of the third year 73 % had recurred, some more than once.)
Often these are determined for sure after surgery after they are removed, but sometimes a urinalysis can give some clues as calcium
oxalate stones mostly develop in acidic urine while struvite stones mostly develop in alkaline urine.
This is sometimes indicative of different stages of disease processes that might, for example, have begun with a
metabolic oxalate stone leading to trauma and infection of the urinary tract and the formation of Struvite layers.
Calcium
oxalate stones also seem to be on the increase in North America - there may be dietary factors involved.
In cats with small
sized oxalate stones, where calculi are identified, they can be effectively treated with adjusting the cat's diet.
Marina Figueiredo, MS Advisors: Dr. Michael Murtaugh & Dr. Jody Lulich Thesis: Gene therapy: A new approach for preventing calcium
oxalate stones Subsequent Position: RePORT Tuberculosis Program Coordinator, Vanderbilt University
The signs will be severe if a stone has moved from your pet's kidney and lodged in one of its
ureters.When oxalate stones are present in a pet's kidneys for long periods without signs or unnoticed, the cat may come to the veterinarian already in uremia, due to the damage the stones have already caused to its kidneys.
In an attempt to
predict oxalate stone formation before it occurs, Waltham pioneered the use of relative supersaturation (RSS) testing in pets.
But the frequency of
oxalate stones did increase in Himalayan, Persian and Siamese breeds (particularly males).
By 2006, the struvite occurrence had fallen to 39 percent while the incidence of calcium
oxalate stones rose to 41 percent.
A Waltham study found that breeds of dogs that generally drink more form
less oxalate stones than breeds that do not (miniature schnauzers vs Labrador retrievers)-- although one can not say for sure that one influences the other.
Remember that a relatively high percentage of dogs will reform calcium
oxalate stones on or off these diets.